Cancellation of aff action

[kamoii]

The following Widget consists of an aff action that takes some time and a button to cancel it.
I thought it would kill aff action if I pressed the cancel button while aff action was running, but it didn't stop even after cancel, and "done" was shown in the log.
Is this an intented behaviour?

testWidget :: forall a. Widget HTML a
testWidget = do
  result <- orr
       [ "canceled" <$ button [ onClick ] [ text "cancel" ]
       , liftAff affAction
       ]
  text result
  where
    -- long taking action
    affAction = do
      delay (Milliseconds 5000.0)
      log  "done"
      pure "done"

[ajnsit]

That seems like a bug. I'll check it out.

[kamoii]

@ajnsit Thanks for your reply!
Would it be OK to create a PR to add a test for this issue?
If I'm not mistaken, it's a problem with the implementation of purescript-concur-core so I'd like to submit the PR to purescript-concur-core.

[ajnsit]

Yeah go ahead!

[ajnsit]

It's definitely an issue with purescript-aff as it's not cancelling the pending timer. I have been thinking about ripping Aff out from concur, atleast concur-core, as it's a big ball of (buggy) JS and prevents us from using Concur for non-js compile targets. I'll also spend some time on doing that.

[ajnsit]

@kamoii I have a work in progress aff-less implementation here - https://github.com/purescript-concur/purescript-concur-core/tree/callbacks

[kamoii]

@ajnsit

I have been thinking about ripping Aff out from concur, atleast concur-core, as it's a big ball of (buggy) JS and prevents us from using Concur for non-js compile targets.

I'm not sure how targeting non-js backend works, but does it mean we have to remove all dependencies including non-direct ones that uses js bindings? If thats true, I have a feeling it's going to be a tough path.

[ajnsit]

Well the hope is that atleast some of the popular libraries will get ported to the new backend by others. One good thing is that Concur-core has very limited dependencies.